Surveying system including an electro-optic total station and a portable receiving apparatus comprising a satellite position-measuring system

ABSTRACT

A terrestrial surveying system comprising an electro-optic total station (1) for combined measurement of angle and distance and a connection to data storage (11) or data processing devices (20), the total station (1) and at least one portable position-measuring unit, which is separated spatially from the total station and equipped with a receiver (3) for a satellite position-measuring system, are connected to one another through a wireless data transfer device (12, 13). The data processing device is preferably set up for determining coordinates, for coordinate transformation from the satellite position-measuring system to the terrestrial coordinate system of the total station and for consistency checking of the data determined.

This application is a continuation of application Ser. No. 07/460,945,filed Mar. 6, 1990, now abandoned.

BACKGROUND OF THE INVENTION

The invention concerns a terrestrial surveying system comprising anelectro-optic total station for combined measurement of angle anddistance and a data transfer interface at the total station which iscoupled to data storage and data processing devices, A total station isalso termed an electronic tachymeter. The angular measurement relatesboth to horizontal angles and also to vertical angles.

Satellite position-measuring systems enable three-dimensionaldifferential position finding with geodetic accuracy A precondition isthe use of a fixed receiving apparatus, tuned to the system, and one ormore mobile sets. It is a characteristic feature of such systems thatposition finding can be undertaken in relatively short time intervals,e.g., in a few seconds, whereby it is also possible to rapidly determinechanges in position. (The "KPGPS" method is the kinematic differentialpositioning with global positioning system method.)

The receiver used in this process is directly equipped with an antennawhose position can be determined with the aid of the system. Because ofthe quasi-optic propagation characteristics of the waveband chosen forthe transmission system, usable reception of the satellite signals isensured only if the receiving antenna lies directly in the footprint ofthe satellites. In the case of mobile receivers, the reception can beinterrupted temporarily or permanently, especially by topographicalobstacles, plant cover, buildings, etc., whereby errors in measurementcan result, or a measurement can be rendered impossible.

SUMMARY OF THE INVENTION

It is an object of this invention to make it possible to survey, withthe aid of a satellite system, points which do not always or do notcertainly lie directly in the footprint of the satellite system.Furthermore, the redundancy of the measurement data determined isincreased, so that reliable measurement results, e.g., for officialsurveying, are obtained.

This object is achieved according to the invention with the featuresdefined by Patent Claim 1.

With the aid of the measurements defined, it also becomes possible todetermine by means of an exceptionally flexible use of the systemcomponents, the coordinates of such points as would otherwise have beenimpossible , or only unreliably capable of being surveyed with the useof satellite position-measuring systems. In this process, thereliability of the measurement results is substantially increased by thepossibility of use in conjunction with conventional surveying methods.On the other hand, the incorporation of characteristic features of thesatellite position-measuring system leads to higher accuracies for themeasurement results derived.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of the invention are explained in more detail below withreference to illustrative embodiments with the aid of the drawings,wherein in schematic representation:

FIG. 1 shows an example of a surveying set, consisting of a totalstation and an attachable satellite receiver for a satelliteposition-measuring system;

FIG. 2 shows the use of a total station with a mounted satellitereceiver to find its own position, and a further portable satellitereceiving apparatus;

FIG. 3 shows an example of geodesy with a total station, without asatellite receiver, and additionally two mobile satellite receivingapparatuses, giving autonomous position finding and data transferinformation to a central data capture station; and

FIG. 4 shows a block diagram of data circuits in the surveying system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a total station 1 for the combined measurement of angle anddistance, which is provided with a positive centering unit 2 forattaching a satellite position-measuring receiver 3. The positivecentering unit 2 has an upper portion 2a attached to the satelliteposition-measuring receiver 3 and a lower portion 2b attached to thetotal station 1. The receiver 3, which is set for the satelliteposition-measuring system, is provided with an appropriate antenna. Forexample, the receiver is designed to receive signals of a globalpositioning system (GPS).

With mounted receiver 3, the position of the total station can bedetermined with the aid of the satellite system. As is indicated byappropriate arrows in FIG. 1, the receiver module 3 can also be detachedfrom the total station 1, and mounted on a plumb rod 4. The receiver 3can then, on the other hand, be used in conjunction with the plumb rod 4for autonomous position finding via the satellite system; on the otherhand, the position of the plumb rod 4 can be surveyed conventionallyfrom the total station 1, as is shown in FIG. 2.

If the autonomous mode of operation with satellite measurements ischosen for the receiver 3 on the plumb rod 4, a wireless data device1213 according to FIG. 4 functions to couple data from the receiver 3 tothe total station 1. Its function is explained elsewhere, together withthe explanation of the data circuits.

The plumb rod 4 is, e.g., telescopically extendable. At its lower end ithas a conventional plumb rod tip S. Finally, it is provided withmeasuring device M, which permits determination of the distance hbetween the plumb rod tip S and the center of the antenna according toFIG. 2.

In parallel with, or supplementary to position finding with the aid ofthe satellite position-measuring system, it is also possible for theparticular position of the total station 1 to be determined in theterrestrial coordinate system with conventional measuring methods, suchas, e.g., free stationing. As an example, FIG. 3 shows the use of atotal station 1 together with two complete satellite receivingapparatuses 5 and 6 in the kinematic differential mode of operation.Assuming that the position of the total station 1 has been eithermeasured by mounting a satellite receiver, or computed by resectioningfrom the positions of the two satellite receiving apparatuses 5 and 6,the aiming points Z1, Z2, Z3 and Z4 can be determined by conventionalsurveying methods from the position of the total station 1. The accuracyof the conventional positions of the aiming points as determinedconventionally on the basis of reference positions from the satelliteposition-measuring system is substantially improved, in this connection,by comparison with measurement results obtained conventionally. It ispossible by means of multiple measurements or combination measurementsto significantly increase the redundancy of the measurement results, andthus the reliability of the measurements.

A coordinate transformation is required in order to compare thecoordinates from the satellite system with those of conventionalterrestrial measurement, e.g., from land topography. This transformationis undertaken in a computer 20 according to FIG. 4, which, via a datainterface 10 is either directly connected to the total station 1 or isarranged at a central data capture point, the measurement data beingtemporarily stored in a memory 11 at the location of the total station.Values S for the measured horizontal distance, and values V for thevertical direction and the horizontal direction H are transferred fromthe total station.

In this way, it becomes possible to determine the transformationparameters which uniquely describe the geometrical relationship betweenthe coordinates of the satellite positioning system and the localterrestrial coordinate system.

The combination of a total station with a satellite navigation systemfurther enables a mutual control of the measurements, in that identicalpoints are determined by the two measurement processes. However, totalstations and satellite units can also survey detailed points completelyindependently of one another.

An additional advantage of the described combination of sets exists inthe case of faults in the mobile satellite receiver systems when thepositions of the antennae can be determined anew with terrestrialmeasurement methods via the total station 1.

Furthermore, the previously mentioned wireless data system between thereceiver 3 of a measuring set and the total station 1 can be seen formFIG. 4. The position data received by the receiver 3 are fed to atransmitter 12 and received at the total station 1 by a receiver 13, andpassed on to the memory 11 or to the computer 20. An infrared system,e.g., is suitable as such a data transfer system. Coordinates can bederived in the total station 1 from the received position data. Thison-the-spot data processing provides a consistency check of the measuredvalues.

The direct data transfer from a measuring set to a total stationcontributes substantially to rapid and reliable reception of measuredvalues. These advantages emerge in a particular advantageous fashion ifthe computer is directly connected to the total station, e.g., in thecase of extensive geodetic measurements.

What is claimed is:
 1. A terrestrial surveying system, comprising:anelectro-optic total station for combined measurement of angle anddistance; a data transmission interface coupled to said total station; adata storage device coupled to said interface; a data processing devicecoupled to said interface; at least one satellite position measuringsystem comprising a first portable position measuring unit comprising areceiver for determining position data; a wireless data transmissionsystem for coupling said measuring system to said total station totransmit said position data to said total station; said total stationcoupling said position data to said data storage device and/or said dataprocessing device; said measuring unit having a first releasablefastening, positive centering device; said total station having a secondreleasable fastening, positive centering device for coordinatedfastening to said first centering device; said first centering devicebeing selectively fastened to said second centering device forpositively connecting said measuring unit to said total station at afirst relative geometrical position, when there is a sufficientsatellite transmission to said first position for reception by saidmeasuring unit, and being selectively fastened to a plumb rod to placesaid measuring unit at a second relative geometrical position having asufficient satellite transmission for reception by said measuring unit,when there is insufficient satellite transmission to said first positionfor reception by said measuring unit.
 2. The surveying system as inclaim 1, wherein:said data processing device performs coordinatedetermination of said position data and performs coordinatetransformation of said position data from a coordinate system of saidmeasuring system to a different coordinate system of said total stationfor consistency verification of said position data.
 3. The surveyingsystem as claimed in claim 1, further comprising:additional portableposition measuring units respectively mounted upon additional plumb rodsfor coordinate determination of additional points which cannot bemeasured from said first position of said total station and/or forcoordinate determination of points by both said first measuring unit andsaid additional measuring units.
 4. A terrestrial surveying system,comprising:a satellite position measuring apparatus for determiningfirst position data defining a first position of said apparatus, saidapparatus including a transmitter for transmitting said first positiondata; a electro-optic total station for combined measurement of angleand distance to produce second position data defining a second positionof said system, said total station including a receiver for receivingsaid first position data from said transmitter; a data processorincluding a memory coupled to said total station for receiving andprocessing said first position data and said second position data; andmeans for positively mounting said satellite position measuringapparatus at one of said first position and said second position atwhich sufficient satellite signal reception exists for accurateoperation of said apparatus, said means for positively mountingcomprising a first releasable fastening, positive centering deviceattached to said measuring apparatus and a second releasable fastening,positive centering device attached to said total station.
 5. A surveyingsystem as in claim 4, wherein said first position and said secondposition are effectively identical and said first centering device isattached to said second centering device for attaching said apparatus tosaid total station at said first position.
 6. A surveying system as inclaim 4, wherein said first position and said second position areeffectively different and said first centering device is attached to aplumb rod at said second position.
 7. A surveying system as in claim 4,wherein said data processor transforms a coordinate system of positiondata received so that said first position data and said second positiondata are available in an effectively single coordinate system.
 8. Asurveying system as in claim 4, further comprising:a plurality ofadditional satellite position measuring apparatuses having respectiveseparate first releasable fastening, positive centering devices attachedthereto for coordinate determination of respective separate positiondata for respective separate positions.